Project Dragonfly: Design Competitions and Crowdfunding

byPaul GilsteronApril 22, 2015

by Andreas Hein

Centauri Dreams readers most likely know Andreas Hein as the head of Project Hyperion, an effort for Icarus Interstellar to examine the prospects for manned interstellar flight, but he has also written in these pages about the uploading of consciousness. Now working on his PhD at the Technical University of Munich, Andreas today tells us about a new Kickstarter campaign in support of Project Dragonfly. Developing under the auspices of the Initiative for Interstellar Studies (of which Andreas is deputy director), Dragonfly explores interstellar flight at the small scale, and as he explains below, leverages the advances in computing and miniaturization that designers can use to change the paradigm of deep space missions.

Humanity has existed for over 200,000 years. It is only about 200 years since we entered the age of industrialization, and in the last 50 years, we have discovered ways of going to the stars [1]. However, the approaches conceived required spaceships the size of a tanker and massive space infrastructures. Today we live in a time when we may soon have the technological capabilities to launch a spacecraft to the stars, but now the spacecraft may be no bigger than a suitcase. Project Dragonfly is the first design study for an interstellar mission based on a small, laser-propelled spacecraft. In this article, I will explain the background of Project Dragonfly and the rationale for the Project Dragonfly Design Competition and crowdfunding campaign.

Many previous approaches for going to the stars have depended on extremely large and heavy spacecraft, based on propulsion systems like nuclear fusion or antimatter. Existing concepts of fusion-propelled spacecraft are as heavy as skyscrapers. Accelerating all the fuel with the ship until it is exhausted is actually not a very efficient way to get to the stars. Project Dragonfly aims at a different approach: The basic idea is not new – it is, in fact, very old. For centuries, humans have travelled the seas using sailing ships. We also plan to use a sail. But a sail which is made of an extremely thin reflective surface. This sail would be illuminated by a laser beam from a laser power station somewhere in the Solar System [2]. The photons of the laser beam push the sail, just as the wind pushes the sail of a sailing ship. And through this push to the sail, the spacecraft slowly accelerates.

However, as the spacecraft does not use any on-board fuel, it can accelerate to very high velocities in the range of several percent of the speed of light. Furthermore, Project Dragonfly builds upon the recent trend of miniaturization of space systems. Just a few decades ago, thousands of people were involved in developing the first satellite, Sputnik. Today, a handful of university students are able to build a satellite with the same capability as Sputnik, one that is much cheaper and weighs hundreds of times less than the first satellite. Recently, NASA announced a prize for the development of interplanetary CubeSats [3].

We simply think further. What could we do with these technologies in 20 or 30 years? Would it be possible to build spacecraft that can go to the stars but are as small as today’s picosatellites or even smaller? It is time to explore and innovate.

The idea behind Project Dragonfly emerged in early 2013 when I visited Professor Gregory Matloff in New York. Matloff, author of The Starflight Handbook, is one of the key figures in interstellar research with major contributions to the area of solar sails. We talked about different propulsion methods for going to the stars and realized that nobody had yet done a mission design for an interstellar laser-propelled mission. Soon after this conversation, Project Dragonfly was officially announced by the Initiative for Interstellar Studies (i4is), with Kelvin F. Long and myself as co-founders.

However, it took another year to get to the point where we were able to organize an international design competition in order to speed up our search for a feasible mission to another star, based on technologies of the near future. One of the challenges for defining proper requirements for the competition was the development of preliminary mission concepts in order to identify performance drivers and showstoppers. Once these preparations were finished, we could launch the competition. See my essay Project Dragonfly: The case for small, laser-propelled, distributed probes for an early competition announcement and scientific backgrounder.

Why a Competition?

Design competitions have a long tradition in the history of technology: The Longitude rewards for the precise determination of a ship’s longitude at sea (1714), the Daily Mail prize for crossing the English Channel by an airplane (1908), the Orteig prize for crossing the Atlantic with an airplane (1919), and more recently DARPA’s Grand Challenge, which focuses on developing autonomous vehicles (2004). These competitions defined a set of requirements — most importantly performance requirements — the technology would need to fulfill. The solutions were up to the entrants.

Competitions offer the advantage that almost anyone can participate. This opens up opportunities for new entrants and innovative solutions, with the potential to disrupt the existing technological landscape [4]. Of course, with Project Dragonfly we are not yet at the level of the “Grand Challenges”. Nevertheless, the so-called Alpha Centauri Awards were announced by Kelvin Long in 2013, offering several cash prizes for relevant areas in interstellar travel. The Project Dragonfly Design Competition is one of the areas for which the Alpha Centauri Prize will be awarded [5].

The objective of the Project Dragonfly Design Competition is to develop a feasible mission design for a small, laser-propelled interstellar mission. Four international university teams are currently working on studies for small, laser-propelled interstellar spacecraft: Cairo University, the Technical University of Munich, the University of California Santa Barbara (UCSB), and Cranfield University, working with the Skolkovo Institute of Science and Technology (Skoltech) in Moscow and the University Paul Sabatier (UPS) in Paris. The final design reports of the teams will cover all areas that are relevant to make the mission a success and to return scientific data: Instruments, communication, laser sail design, power supply, secondary structure, deceleration propulsion, etc. Furthermore, both technological as well as economic feasibility will be assessed by the teams.

Image: The Project Dragonfly design team at Cairo University, made up of aerospace and communication engineering students, is one of four working on laser sail design.

The teams will meet with members of i4is in London at the headquarters of the British Interplanetary Society this July in order to evaluate their designs. The results from the competition will serve as a basis for future technology development of such a mission.

Project Dragonfly Kickstarter Campaign

The Initiative for Interstellar Studies has now launched the first ever Kickstarter campaign for supporting an interstellar design competition. The funds raised during the campaign will allow us to support the student teams during the competition. The campaign began on the 15th of April and will run until May 14th. All supporters will receive unique and exclusive rewards for their pledges, among them T-shirts and posters with an image of the winning team’s spacecraft, painted by the grand master of space art, David A. Hardy. The campaign is further supported by renowned space artist Adrian Mann. Further awards consist of a 3D-printed version of the winning team’s starship as well as early access to team reports, a signed version of the Beyond the Boundary book edited by Kelvin F. Long, etc.

IIRCthe biggest challenge for a long range pico sat craft would be communications – I’ll be interested to see what solutions are proposed! And I’ll be donating.
Given that the kinds of speeds we’re talking are single digit percentages of c, wouldn’t an interstellar precursor mission be a closer fit as a description for this? ‘A few percent…’ sounds like five percent or less to me, which means eighty years plus to proxima centauri….

Not sure if your far enough along to know, but what would something like this cost? I was always interested in a small scale interstellar mission as a proof of concept for a manned mission maybe before the end of the century. It would be great if this could be made to happen in the coming decades.

Actually, very long-term missions (of several hundred years or more) have been discussed here before. I think it’s unlikely we could guess what will be of scientific value for so far in the future, but if we can make a probe that lasts that long and returns data throughout its mission, it’s worth trying. We’ll get something out of it and if our descendents find it useful they’ll keep it going. If not they’ll switch it off. The choice will be theirs but at least we’ll have given them the choice.

1) less mass means less energy need for propulsion
2) smaller size means less probability of impacting an obstacle at high speed

The advantages speak for themselves, i think. Also, with a beamed propulsion concept you save the mass for the propulsion system and the propellant, which strikes me also as a no-contender solution for interstellar travel. That is, of course, not a solution for manned spaceflight. NTRs are still around for heavy duty, such as getting large payloads to leo and around the solar system.

If you think about where we could be had we not invested the majority of our resources into two world wars, a cold war and now the next cold war it is really tragic. The biggest barrier is still philosophical in nature. If we can’t overcome that we can’t go anywhere.

Sadly we seem to need a certain level of conflict with each other to progress technologically at speed.
A probe to interstellar space would be, IMHO a very worthwhile mission by itself. A trajectory towards proxima centauri could be selected, with the option of keeping the probe on all the way there, but without it being the main mission.

@swage – without 2 hot wars and a cold one, we might not have invested resources in spaceflight at all. Rockets are almost a direct result of funding the German Rocket Group. High power lasers have been developed by the military f0or a variety of offensive and defensive purposes. We have to be a bit careful about determining history counterfactuals. But yes 2 global hot wars were an immense waste of resources despite the technical achievements that resulted. They also changed social attitudes and redistributed wealth as side benefits.

Probably not possible but wanted to put the question out there. Would it be possible to accelerate this picoStarships on a large magnetic accelerator orbiting the moon or on the moon’s surface to near the speed of light and shoot it to Alpha Centauri? There is probably something I am not taking into account but, why not?

“If you think about where we could be had we not invested the majority of our resources into two world wars, a cold war and now the next cold war it is really tragic. The biggest barrier is still philosophical in nature. If we can’t overcome that we can’t go anywhere.”

As much as I agree with you, I have to wonder what kind of space program we would have at all without the Cold War and the technological developments from the first two world wars? Governments (the ones with the money) pretty much ignored the various rocket societies that appeared in the 1930s until they realized the military value of a bomb being transported by a vessel that could not easily be shot down.

In the original Cosmos series, Carl Sagan mused where we might be now if the Greek Ionian scientists like Democritus had been revered rather than the more esoteric Pythagoras and Plato. He went so far as to imagine manned starships departing Earth in our time bearing Greek words and symbols on their hulls.

As much as I would like such things to be true, reality tends to go with populations that want to be protected and sated by governments all too willing to take control and not let people get too smart except when it benefits them and can make lots of money. This aspect of human nature will only change when humans radically change, and will not get better so long as we have such huge populations to maintain.

I think flight time would matter for such a small probe. Designing a nuclear battery to last over 400 years would be quite a challenge. Using beamed power for such a long time would also be very difficult. A generation starship might be easier to do than a tiny probe over centuries (easier, not cheaper).

Dragonfly couldn’t leave the sail unfurled for the entire trip without loosing most of it to erosion. So you might use it to reflect power from the laser beam to solar cells while it lasted. Remember, Daedalus had a 9mm beryllium erosion shield. Dragonfly would also need this, so the frontal cross-section would have to be pretty small to keep the shield weight down. You could probably improve on beryllium with a layered ceramics, metals and plastics shield, but not by that much.

Dragonfly would probably want cameras off all sides to get good stellar parallax views during the trip and for the encounter at the target star. Sensor data would exceed communication capability by many times, so Dragonfly would have to decide what to send back on its own.

As to cost, the laser, communications and collimator would be the major costs, but you could use the laser and communicator (probably also laser receiver) again. Even at $1M/kg, Dragonfly would probably only cost a few million to build. The only other large cost would be the communication listening time, which could be mostly automatic. And of course taxes, licenses and government fees.

“If you think about where we could be had we not invested the majority of our resources into two world wars, ….”

So true, and currently we’re spending $2 trillion a year on the world’s militaries, which doesn’t include the increase in the global GDP that we would see if every country had a modern economy and infrastructure.

Even 10% of that, $200 billion a year, if it’d been invested in space research and development would’ve put us way ahead of where we’re currently at. Over a 20 year period it would’ve allowed space stations that would’ve put the ISS to shame, not to mention a moon base, and possibly a mars one.

With the advances in technology we might’ve even launched the first probe to the sun’s focal point by now, albeit even under the best circumstances it would still be decades from its goal.

But alas we humans are addicted to war, and besides, it’s the perfect way to keep people inline. Without the “other” who knows what might happen…. Peace? Such a fearful concept.

It’s not that space exploration is too expensive, it’s just that we got other more important priorities.

Luis, to reach 1%c at 1,000 g’s (9,800 m/s^2) would require a magnetic accelerator 45,855 km long, over half the diameter of Jupiter. You could increase the g’s and shorten the track, but you can see the scale is way out there.

While we all agree that conflicts drive technological development, especially in the case of missile systems and lately lasers, i am in no way convinced that conflicts are strictly spoken a necessity for technological development. It can be a huge motivator, granted, but for unrelated reasons.

There are a couple of problems:

1) a certain chance that a major technology loss occurs through damage
2) beyond the scope of military applications there is a motivation shortfall and the initial problem persists – maybe on another level, but its still there
3) conflicts are expensive and tie up the bulk of resources in unrelated projects

Conflicts drive technology, but that isn’t really a solution to a full commitment to a space program for its own sake. Of course people tend to take what they get, Von Braun is a prime example of that and yes it yields results.

But its in no way competitive to a true commitment to space exploration. It is one mainly occupied conflicts developing some space capabilities along the way.

The question if we had developed the systems in use today is certainly valid. Probably not. But doesn’t that actually underline the need for reevaluating priorities instead of countering the assumption?

Just imagine for a second the exploration spirit presiding over conflict driven geopolitics. I know we are not that kind of civilization but what… if? If the efforts had been committed to a space program? A moon base? A orbital ship assembly? A mars colony? Manned, interplanetary exploration vessels?

The main obstacle, so to speak, to humanity developing a space infrastructure is humanity itself.

There seems to be a certain selection bias for advancing a species along the kardashev scale. My bet is on committing massive resources on a global scale on conflicts will not get us very far.

A 10 year flight at .02 c would be a fantastic success. It would real time data and proof of concept. 80 years of progress based on what may be learned in that 10 years would be far more profitable than 80 years of stagnation monitoring a flight to nowhere.
Life is a journey of profound discovery. . .

A couple of points. I am surprised that you say “nobody had yet done a mission design for an interstellar laser-propelled mission”, and then reference Robert Forward’s 1984 article which does just that. Perhaps you meant nobody had yet done a design study as detailed as the one which you’re planning?

I am also surprised that you repeat the customary claim: “Accelerating all the fuel with the ship until it is exhausted is actually not a very efficient way to get to the stars. […] However, as the spacecraft does not use any on-board fuel, it can accelerate to very high velocities in the range of several percent of the speed of light.” I am sure you know that in terms of energy efficiency, a rocket operated near optimum efficiency (mass ratio ~5) beats a laser sail accelerated to such low relativistic speeds. The laser sail is only energetically more efficient after it’s been accelerated to above around 0.7 c. Of course, for the sort of small spacecraft you’re thinking of, this probably doesn’t matter so much.

In the event, the relative costs of different propulsion options will be strongly influenced by what power technologies are already in use for domestic purposes. So if you can make a case for large-scale use of beamed power within the Solar System before you start the probe, that would help you.

Without the fear of radiation developed due to the possibility of nuclear war, we might even have played with Orion a bit more – megaton space stations launched in one go…. Still, given we did build enough nuclear weapons to eliminate our civilization, that fear was a necessity, however irrational it has become in regards to things like nuclear energy, and propulsion.

Project Dragonfly though might be better suited to studying how to get a probe to the sun’s focal point. Imagine mass producing such probes by the thousands, and sending them to points where they can observe other systems of interest. They would only require a fraction of the speed needed for an interstellar mission, and would be able to start producing useful data in a decade or two.

The lower speed, and shorter time period, would enhance the chances of success, but still provide a proof-of-concept mission. One could even imagine a larger vessel that gets up to 1/1000 the speed of light, and then releases the probes, which would then use the sun’s gravity to alter their trajectories. Twenty years later the data starts pouring in ….

You also have to hope the people back home manning the laser will remain loyal to the mission and not decide it will make a great weapon to use on their enemies instead.

swage, while you are right that technological innovations do not always and should not be dependent on arising from conflict, the sad truth is that is still much of the reason why humans do such things as spacecraft propulsion to begin with.

Without the Cold War I doubt we would have much of a space program and more than likely never would have had Apollo, because it is pretty clear that acquiring science knowledge for the benefit of humanity is not enough of a motivation for those with the money to be generous.

I see the same situation for developing a powerful laser system. Such a device will likely come about as an offshoot of a military project, not because a group of scientists want to explore Alpha Centauri. Ironically it may be conflict that gets humanity to the stars, if we survive such a situation in the first place.

“Don’t be so gloomy. After all it’s not that awful. Like the fella says, in Italy for 30 years under the Borgias they had warfare, terror, murder, and bloodshed, but they produced Michelangelo, Leonardo da Vinci, and the Renaissance. In Switzerland they had brotherly love – they had 500 years of democracy and peace, and what did that produce? The cuckoo clock.”

NASA gets $18 billion annually and that number is always being threatened by Congress. The US Department of Defense currently gets $670 billion annually. The seventh film in the Fast and Furious franchise made one billion dollars in just 19 days.

Forward 1984 paper: It depends on what you consider “design”. His paper contains a rough, “back-of-the-envelope” assessment of an interstellar probe mission. I indeed consider a “design” a more detailed assessment of the mission, including all spacecraft subsystems.

Rocket propulsion: Again, this depends on what form of efficiency you consider. If efficiency is propulsive efficiency, “energy converted to thrust / total energy”, you may be right. However, the efficiency of our recent Project Icarus Ghost ship was similar to the one for a laser sail. If you consider “payload mass / total spacecraft mass” as a figure of merit, the laser sail is clearly superior to a rocket.

‘Probably not possible but wanted to put the question out there. Would it be possible to accelerate this picoStarships on a large magnetic accelerator orbiting the moon or on the moon’s surface to near the speed of light and shoot it to Alpha Centauri?’

These although small massed craft will have huge momentums approaching the speed of light and there is nothing powerful enough to counter act that outward momentum which would cause them to collide with the walls of the accelerator. There is also the issue of the effects of powerful magnetic fields on delicate electronic circuits in the probes and further small craft will have radiation issues due to their small sizes.

As for a solar focal point mission there is no need to go all the way there, you could get the same resolution but less light gathering power if the probes made their way along the light cone and communicated between each other or a central processing craft. A laser system would be ideal in propelling numerous craft at once just by using repeating small beam alignment changes to push each component of the system.

I thought I would revisit this discussion after watching a video of Garrett Reisman at Keck Institute last year. He was talking about a counterpoint to many of our perceptions of war driving technology, the golden age of flight between the WWs. Government budgets were very constrained and yet huge advances occurred in aircraft technology. Maybe there is yet hope.

swage, the ‘war accelerating progress’ problem is much deeper than you imagine.

London during the blitz is a classic case where objective measures of stress, such as suicide and heart disease plummet to all time recorded lows as everyone works together. On the anecdotal level, everyone who recounts those those times seems to do so with a smile, even while explaining rationing etc. Many describe it as the best time of their lives, and men at the front usually describe the new ‘brothers’ they meet as the deepest friendships of their lives.

Though it might be easy to assume that the wartime economy goes into hyperdrive only because of government expenditure, there is more to it than that, and harnessing these effects in peacetime is an ability that has, so far, eluded us. On the brighter side we almost got their with Apollo, but not quite, and the progress we did make quickly faded with time. I doubt we will be back to the Moon soon.

This is one possibility of rallying people to a cause, but i doubt it is the only possible path to follow. To be honest, and this is not to be taken as a statement against comradeship during difficult times, i think it is a less then optimal route which will lead us ultimately (and evidently) off track, getting us lost, quite possibly up to the point total disaster.

Investment in conflicts is ultimately investment into self-destruction, especially as we gain access to more and more destructive weapons, which is also a maturation of ability, strictly spoken, which is a catastrophic paradigm to follow.

Let me emphasis that: catastrophic – not only because its irrational, which is bad enough on its own, but also because its self-destructive in nature. Ask a psychiatrist about such behavior by individuals, they know all about it. Its suicidal. Let me put it bluntly: we are currently following a suicidal paradigm of thought. It is not an acceptable. Impossible!

My perception is not technology but rather maturity as a species being the biggest barrier to… advancing the species beyond its current boundaries. There is currently not much effort in that direction, quite on the contrary.

Maturation of ability also mandates maturation of responsibility (its a horrible movie trope, alright). The truth is that with all our technological prowess we are infantile when it comes to responsibility on a geopolitical scale.

We reached a turning point during the Cuban Missile Crisis and its impact on geopolitics (shift from conventional conflicts to “deterrence”) can’t be overstated. But that is not the end of it. It is the beginning.

It is a development that is an evolutionary necessity, so to speak and our current position is quite alright in the transition from our animalistic survivalist nature to changed survival priorities. You can’t simply brush aside billions of years worth of evolutionary optimization to now altered realities. It is… understandable. I still hope the process will be a short transition without any major relapses.

In short: we have to overcome our inner beast. Better sooner than later, before somebody gets hurt seriously.

swage, the political ideas expressed here are somewhat interesting, but hardly new. More like thousands of years old. The history of the world is ripe with such sentiments. Read Plato, or the histories of ancient Egypt or Rome, or any other civilization and you will read of people decrying war. War and poverty have been staples of political control for millennia and will remain so for the foreseeable future. The science fiction book, ‘The Mote in God’s Eye’ by Niven and Pournelle ran through many more of the political options for a species trapped in one solar system by fate than you have covered here, and it is only one point of view.

The technology is much more interesting to me. Let’s say for the sake of argument that the politicians find a solution to creating large lasers that do not endanger people on Earth, such as allowing them only to be used from Earth’s surface into space or on the far side of the Moon.

If the lasers can be built, the Dragonfly concept becomes technologically interesting. How small could they be? I have done a quick design to see if the payload section could be limited to 1,000 grams and a volume of 1,000 liters. (The old Cubesat standard.) It might be doable.

Transmit power from the target star would be iffy at best, but further calculations should yield how large to scale the final probe. The power could be solar cells near the launch and at the encounter star. In between, it would probably be nuclear thermal to keep the parts from freezing, but would probably have to be kept in sleep mode for most of the cruise phase.

Communications transmit to the probe would be on the beam power laser during launch. From the probe on a laser pulsed at a different color. Instead of batteries, the power storage on board would be capacitors. They should last much longer than batteries.

Rough design so far is 35.7 mm diameter, 1,000 mm long. Erosion shield in front: 3 mm beryllium (metal provides a spray of lower energy particles that can be dealt with by lower layers), 121 mm polyimide aerogel (0.07 g/cc, provides low average molecular weight and distance from the initial impact), 3 mm boron nitride (hard stop with low secondary emissions). Behind the shield: 150mm capacitors to power sensors, these would also provide some forward shielding; 14 sensor bays as long at the diameter; 150 mm capacitors to power communications; data storage and processing; and the laser transmitter.

Real diameter, and therefor mass would depend on the desired focal lengths for the optical sensors. Laser and sail would be sized to the payload. Given the communications distance involved, and the fact that I can’t think of a way to power the probe for the entire trip, return data would have to be automated. Staring into a star even to pick up a laser beam would be difficult, but I have no idea what the laser power of the transmitter would have to be.

I think any design that can not get to the target star within the career span of a scientist starting as a grad student and ending as a retiring professor is utterly useless. That means about forty years max which implies at least about 10%c. If it cannot be done then wait till it can be done.

Waiting doesn’t make progress automatic. Dragonfly is a design competition for college students to learn what can and cannot be done, in theory and maybe in practice. They will learn starflight theory and engineering mass, power, cost and volume budgets, space systems design and very, very long distance communications principles. They will also be the people who determine what areas of study are needed for progress in the field to continue.

A 1%c probe would probably be passed in flight by a 2%c probe if the technology becomes available. And a 3%c probe may pass a 2%c probe in flight. But 10%c may prove to be impractical for probes going in all directions. Slower probes may eventually return data from thousands of stars.

It does mean that scientists would have to document their work: where, why and how the probe was made and launched, for the sake of the next generation that would collect the data. Not standard practice today, but a far cry from having to evolve to a ‘more mature species’.

My criticism was not of the Dragonfly design contest itself but of actually paying for a mission less than .1C.

I have a minor background in particle physics so here is a weird concept regarding a 0.1c ability. At the sustained power of about 10MW about 20micrograms could be accelerated to 0.1c every second. A continuous stream of such particles (or even parts) might be launched in such a way that over a year or two a KG of material moving at about 0.1c could hypothetically self organize into a coherent probe if designed with that in mind. Cost of power would be about ten million dollars per year at .1$/KWHR. The accelerator and power source would be space based. Ten times the power could get to about a third of light speed. It could be called Stardust.

Interesting concept, Robert. I will have to think about it. Mostly, can a particle beam be self-organizing in that way? All the particles would have to be planned to meet at the exact same position (relative to the moving probe) after about 1.584 years of flight (20 micrograms for 50 million seconds). Particle beam epitaxy at ever increasing distance? (20 µg are rather large particles) Size could vary, mass could vary; with distance.

Robert, I can’t see how it would work. The relative velocity of all the particles would have to be very low in order for them to connect with each other. Since they would be sent out over a period of over a year, it would take decades for them to assemble. And keeping a particle beam focused for decades would be quite a challenge, since they would also have to be self-focusing.

‘Transmit power from the target star would be iffy at best, but further calculations should yield how large to scale the final probe. The power could be solar cells near the launch and at the encounter star. In between, it would probably be nuclear thermal to keep the parts from freezing, but would probably have to be kept in sleep mode for most of the cruise phase. ‘

There is the possibility of using the kinetic energy of the probe as a source of energy by the use of a coil that would interact with the interstellar medium to produce the power needed for communications and craft processes. The kinetic energy of a probe travelling at 10% to 30% the speed of light is enourmous giving ample power.

‘Rough design so far is 35.7 mm diameter, 1,000 mm long. Erosion shield in front: 3 mm beryllium (metal provides a spray of lower energy particles that can be dealt with by lower layers), 121 mm polyimide aerogel (0.07 g/cc, provides low average molecular weight and distance from the initial impact), 3 mm boron nitride (hard stop with low secondary emissions). Behind the shield: 150mm capacitors to power sensors, these would also provide some forward shielding; 14 sensor bays as long at the diameter; 150 mm capacitors to power communications; data storage and processing; and the laser transmitter.’

The capacitors could become shorted by the plasma radiation of an impact which could blow the whole lot up.

No, the ideas are not new and yes, we can concentrate on technology and by all means conceiving star ships is a technical endeavor. But i wouldn’t brush it aside as historical sentiments. That would be a pitfall, i guess. There is a social component involved and at this point i am pretty convinced that mastering society is just as important as mastering the necessary technology itself, creating the necessary conditions where such projects are possible. If you want to go through with it, that is, and not just do blueprints and a mandatory project here and there. There have been undeniably changes. If we hadn’t discovered nuclear technology i am pretty convinced the Cold War would have turned into a hot one, leading right into the next big conflict. Things changed already. Slowly we are forced to realize how truly useless this attitude is and that is a fairly recent development. At a gunpoint level, so to speak. You could say we are well on our way already.

I am currently… well… reading is too expressive, more like “glancing over” Thomas Hobbes “Leviathan” and there are some interesting remarks. His religious attitude is quite interesting and albeit i have problems with theological perceptions, i have to say that he has a rather rationalized perception of things. Most remarkable i that he doesn’t judge as good or bad, but rather as a systematic outcome from a given set of realities.

But i guess that doesn’t really belong here :)

Lets just say that i am not convinced this has to be the status quo, i think there is room for improvement.

Robert, I can’t see how it would work. The relative velocity of all the particles would have to be very low in order for them to connect with each other. Since they would be sent out over a period of over a year, it would take decades for them to assemble. And keeping a particle beam focused for decades would be quite a challenge, since they would also have to be self-focusing.

Nonetheless, I think the idea of self-assembly of previously launched components is fascinating. Mason Peck’s ‘sprites’ come to mind here, with the possibility of future generations of these sent out as ‘swarms’, and perhaps with highly advanced future tech, capable of such self-assembly for a variety of mission scenarios. Cool idea.

“A well known American writer said once that, while everybody talked about the weather, nobody seemed to do anything about it.”, from Hartford Courant, attributed to both Mark Twain and/or Charles Dudley Warner.

That’s the way I feel about politics. I never said it was out of place here. I am well aware that politics is the driving factor in space exploration. I just don’t think talking about it makes any difference. There is very little you can do about it. Average citizens are just ‘bugs in a jar’ to politicians.

Nuclear power was a turning point in power and politics. At over a million times the specific energy of chemicals, nuclear could propel spacecraft to more than a thousand current rocket speeds. Enough to reach for the stars. But every nuclear rocket is a nuclear bomb if pointed the wrong way. Military planners and some politicians understand this, and they are not about to let nuclear rockets take off unless they are in control.

Not “historical sentiment”. It’s ‘historical’ and ‘sentiment’ if you don’t understand that war is just a tool of politics. Not the only tool. Propaganda, religion, debt, the promise of money, control of communications, and starving out poor enemies are all used by powerful people to stay in power, and I’m sure they have many other tools in their toolbox.

Nuclear changed the nature of war, but human nature hasn’t changed. The political game is still the same. I am pretty sure politicians mastered society a long time ago. If that’s the paradigm change you are looking for, I don’t even see that it has started to happen yet.

Paul, sprites are interesting. The concept of self-assembly is interesting. The math is the problem:

“Particle ‘A’ leaves the station on January 15, 2020, moving 1% of the speed of light. Particle ‘B’ leaves the station on July 30, 2021, moving 1.00001% of the speed of light. How long does it take Particle ‘B’ to catch up with Particle ‘A’? If their relative velocity is greater than 0.00001% of the speed of light, what happens when they meet?”

Michael, with laser sails, like John Freeman said, “we’re talking are single digit percentages of c”. Still fast enough to convert to power, but in a small probe, the antenna would then be the issue. Maybe. I haven’t done antenna calcs in thirty years, and they have come a long way since then.

The forward shielding would be designed to take care of an impact plasma. But it is still a high radiation environment, so catastrophic discharge would still be an issue. Maybe thin flat capacitors (ceramic, maybe barium titanate with gold plates so an ionic short wouldn’t oxidize the plates. I still have to rule out batteries as impossible for such a long mission.), with plates perpendicular to travel and one per payload bay would minimize the danger. Most of the payloads would have to be fairly low voltage. Transmitter power supply at the back of the probe would be the highest risk. Don’t charge it all until encounter. But you are right. A wrong radiation hit when fully charged would destroy the probe. Needs more work:)

Yes, it is a long shot concept with probably far more problems than it solves but at least at the low end we could send a few kilograms of mass to nearby stars without waiting for millennia if we wanted to (not that we ever would!). Such particles really would have to be micro or nano machines to assemble. Assembly would have to happen essentially continuously along the route not all at once at the end. The earliest structure near the beginning of the journey might be optimized to spread out and attract the newly arriving mass. Velocities would have to be controlled to be a slower at first and fastest near the end. Perhaps the throw time should be reduced to a few months with greater power. Sophisticated enough devices might be able to use a percentage of their mass to navigate around for the assembly process. Possibly there could be a laser field guiding the particles together along the way.

Anyway it is fun to think about such things while hoping for something truly transformational.

A successful swarm approach could mimic the functionality of stem cells. Each picoprobe could have the mission software downloaded in a tight package — similar to DNA — along with the capacity to join with any other picoprobe to carry on any function — like a stem cell.

That way, you don’t have to worry as much about catastrophic impacts, misdirection of individual probes, etc., etc., etc. along the way. Figure in a probable loss rate and design the swarm to form up and function even with those projected probable losses. Just like life functions at many levels, overproducing individuals to ensure the survival of the species.

For example, a multitude of picoprobes could form up to make a large enough array for communication back.

And “just fire all your guns into space” at once rather than sending a stream of the things sequentially over time. Shine your laser on the swarm and let fly all at once, so enough of them arrive substantially together.

If the kinetic energy concept discussed in a comment above works, then that covers that issue. If not, might have to put a grain of some radioactive material in each one that would be nonharmful to anyone intercepting them along the way.

Re: a space laser maybe being aimed back at Earth as a weapon, it’s my understanding — I’m a liberal arts grad not a scientist — that some lasers operate fine in space but not so well through atmosphere. Use one of those.

Speed the ultra low mass cluster up to .1 c, and it looks like a swarm or cloud approach could do an interstellar probe mission in one professional lifetime.

The swarm either can physically join up along their edges to form a single large light sail or fly in formation to form a rotating composite light sail disk. A rotating disk should help with maintaining integrity of the formation and overall directional stability. Again, with a swarm, if an individual picoprobe is knocked out by a collision with space dust, it wouldn’t necessarily be a big deal to discard and then patch with another member of the swarm.

‘Re: a space laser maybe being aimed back at Earth as a weapon, it’s my understanding — I’m a liberal arts grad not a scientist — that some lasers operate fine in space but not so well through atmosphere. Use one of those.’

There is a laser technic in which the atmosphere absorbs a little light (another laser) and expands to form a lens for the beam behind it, a sort of self focusing beam.

In Centauri Dreams, Paul Gilster looks at peer-reviewed research on deep space exploration, with an eye toward interstellar possibilities. For the last twelve years, this site coordinated its efforts with the Tau Zero Foundation. It now serves as an independent forum for deep space news and ideas. In the logo above, the leftmost star is Alpha Centauri, a triple system closer than any other star, and a primary target for early interstellar probes. To its right is Beta Centauri (not a part of the Alpha Centauri system), with Beta, Gamma, Delta and Epsilon Crucis, stars in the Southern Cross, visible at the far right (image: Marco Lorenzi).

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